What does SSO stand for?
SSO stands for Single Sign-on. Single sign-on: one authentication grants access to many applications. It is convenient, but it makes the identity provider a high-value target.
With SSO a user signs in once to an identity provider and then reaches every connected application without typing credentials again. Applications trust a token or assertion issued by the identity provider instead of keeping their own passwords. It cuts password fatigue and makes joiners and leavers easy to manage, but one stolen session opens many doors, so it is paired with MFA.
SSO in practice: an example
An employee signs in to the company portal in the morning. Opening the HR system, the ticketing tool and the email client needs no further sign-in, because each one accepts the identity provider's assertion. When she leaves the company, disabling one account closes all three.
What SSO is confused with
SSO vs SAML: what is the difference?
SSO is the experience. SAML is one of the protocols that deliver it, alongside OpenID Connect and Kerberos. What SAML stands for
SSO vs MFA: what is the difference?
SSO is about how many times you authenticate, MFA about how strongly. What MFA stands for
Which exams cover SSO?
SSO is on the official CompTIA acronym list for all four exams covered here.
- Security+ SY0-801: 4.5 (Security Operations).
- CySA+ CS0-004: on the acronym list, not tied to one objective.
- Network+ N10-009: 4.0 (Network Security).
- A+ 220-1201 and 220-1202: 220-1202 2.0 (Security).
Each number is a CompTIA exam objective and the name in brackets is its domain. The exam puts the term in a scenario; it does not ask you to recite the expansion.
Check yourself: two practice questions
Written by CertSprint for this page. They are not taken from any exam.
1. What is the main security drawback of single sign-on?
- Users need more passwords
- One compromised account gives access to many applications
- Applications can no longer be audited
- It only works on wired networks
Show the answer
B. One compromised account gives access to many applications. SSO concentrates access behind one sign-in. That is why it should be protected with MFA and session controls.
2. A leaver still had access to a cloud tool for two weeks because it kept its own local passwords. Which change prevents a repeat?
- Connect the tool to SSO through the identity provider
- Raise the password length to 20 characters
- Add a second firewall
- Enable disk encryption
Show the answer
A. Connect the tool to SSO through the identity provider. With SSO the identity provider is the single place where the account is disabled. Local accounts in each application are easy to forget.
Sources: NIST glossary: single sign-on; Microsoft Learn: What is single sign-on in Microsoft Entra ID?. The acronym and its expansion come from CompTIA's official acronym lists, linked from each exam glossary above. The explanation, example and questions are CertSprint's own, checked against these sources on 11 November 2026.